Dwyer 204 User Manual

Magnetic Type Liquid Level Contols

TYPES

TYPES

TYPES

201
251

1271

203
253

1273

204
254

1274

TYPES

TYPES

TYPES

211
221

213
223

214
224

Series 201, 203, 204, 251, 253, 254, 1271, 1273, 1274 - Sealed Housing with Stainless Steel Float
Series 211, 213, 214, 221, 223, 224 - Flanged Steel Float Chamber with Removable Steel Float

Installation and Operating Instructions

Bulletin O-421C

Operating Characteristics

When the float rises to the operating point, the switch or switch­es are actuated by the mutual attraction between a magnetic
plunger attached to the float within the float chamber and a mag­net attached to the switch operating assembly. When the float
drops, the magnetic plunger is moved out of the field of the mag­net on the switch operating assembly and the switch or switches
are restored to their original position by gravity.

The magnetic plunger attached to the float moves within a tube
within the switch enclosure. The switch unit is mounted on the
tube singly or in pairs. Type 1271 - Single Stage Only.

Explanation of Type and Code Numbers

Example: Type 201G-4820-C1-60.
201 is the type number of the control; letter “G” denotes enclo­sure; -4820 designates circuit arrangement; C1 denotes materials
of construction; 60 indicates pressure rating and specific gravity.

Enclosures
General Purpose enclosures are identified by the letter ‘G: in

type number as in 201G, 1273G.

Weather Resistant enclosures are identified by the letter “W” in
type number as in 204W, 211W.

Explosion-proof enclosures are identified by the letter”E” in type
number as in 201E, 1274E.

Explosion-proof -- Vapor-proof enclosures are identified by the
letters “EV” in type number as in 203EV, 223EV.

Wiring

Wire in accordance with local electrical codes or follow equipment
manufacturer’s instructions.
Align wiring block to face conduit opening and tighten brass screw
of switch assembly.
The 3/4˝ NPT conduit connection (on all types can be rotated 360°
to facilitate wiring.
Do not overload electrically. See rating stamped on nameplate.

Operating Adjustments

Level Adjustment (Single Stage Only) Types 201, 203, 204, 211,
213, 214, 221, 223, 224, and 251, 253, 254 only. When single
stage controls are shipped from the factory, the switch operating
mechanism (illustration No. 11) is positioned at the center of the
armature tube. The operating level can be raised approximately
one inch by moving switch mechanism up to the top of the arma­ture tube. Operating level may also be lowered one inch by mov­ing switch mechanism down to bottom of armature tube. To obtain
either operation, loosen clamp screw (illustration No. 11) before
raising or lowering switch assembly. Be sure to tighten clamp
screw after the desired adjustment is made.

Type 1271, 1273, 1274 (Single Stage Operation) the switch oper­ating mechanism must rest at the bottom of armature tube against
enclosure base.

LIQUID LEVEL CHANGES IN INCHES FOR SWITCH OPERATION

Series 201, 203, 204, 221, 223, 224, 251, 253, 254

Minimum Specific Gravity 0.6

Special Features
Semi-Automatic (with manual reset) operates automatically on

level fall only - manual reset required on level rise. This operation
identified by the letters “RU” in type number as in 201GRU.

Wide Differential (Single Stage) available only for controls with
mercury switch contacts. Provides double the fixed level change
(“B: in Liquid Level Change Table) between on and off switch
operation. Identified by the letter “D” in type number as in 201GD.
Type 1271 Not Available.

440 Volt Service

Identified by the digit 5 in circuit specification No. such as in ­5820, -5821. For two-stage operation 440V is limited to SP-ST in
each stage.

Location -- Mounting

Select location recommended by equipment manufacturer. Mount
all controls vertically and be sure that control switch mechanism is
level.

MERCOID DIVISION

DWYER INSTRUMENTS, INC.
P.O. BOX 258 • MICHIGAN CITY, INDIANA 46361 U.S.A.

Single Stage Operation

“A” is Adj. ±1˝

Sp. Gr.

1.0

“A”
6-3/4˝
7-1/2˝

.6

“B”

Code

3/4˝

1˝

C1-60

See Illustration No. 10

Single Stage with Wide

Differential “A” Not Adjustable

Sp. Gr.

1.0
.6

“A”
7-1/2˝
8-1/4˝

1-3/4˝
1-7/8˝

“B”

Code

C1-60

Two Stage Operation

“A”- Not Adjustable

Sp. Gr.

1.0
.6

“A”
5-3/4˝
6-1/2˝

“B”

3/4˝

1˝

“C”

7-3/4˝

9˝

“D”

1˝

1-3/4˝

“E”

2˝

2-1/2˝

Code

C1-60

Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]
Lit-by-Fax: [phone]

Bulletin O-421C

"D"

"E"

"B"

"A"

"C"

CLAMP SCREW

FLOAT ROD

FLOAT

3/4 NPT COND CONN

ROTATABLE TO 360°

MERCURY SWITCH

ASSEMBLY

ARMATURE TUBE

Page 2

Illustration No. 10

“A” - level at which single (or lower
stage) operates on level rise.

“B” - operating differential single
(or lower stage) - drop in level to
restore switch to original position.

“C” - level at which upper stage
operates on level rise.

“D” - operating differential of upper
stage - drop in level to restore
switch to original position.

“E” - increase in level above “A” to
operate upper stage.

LIQUID LEVEL CHANGES IN INCHES OF WATER FOR-

Series 201, 203, 204, 221, 223, 224, 251, 253, 254

Minimum Specific Gravity 0.75

Single Stage Operation

Specific Gravity 1.0 & .75 -

“A” is Adj. ±1˝

Illustration No. 11

Single Stage with Wide

Differential “A” Not Adjustable

(See Illustration No. 10)

Sp. Gr.

1.0
.75

“A”

7-1/4˝

8˝

3/4˝

Sp. Gr.

1˝

C1-75

See Illustration No. 10

1.0
.75

“A”

8˝

8-3/4˝

“B”

2˝
2˝

“B”

Code

Two Stage Operation

“A”- Not Adjustable

Sp. Gr.

1.0
.75

LIQUID LEVEL CHANGES IN INCHES FOR SWITCH OPERATION

“A”

6-1/4˝

7˝

Series 211, 213, 214, Minimum Specific Gravity 0.6

“B”

3/4˝

1˝

450 PSI at 100°F, or 300 PSI at 500°F.

Single Stage Operation

“A” is Adj. ±1”

Sp. Gr.

1.0
.6

“A” - level at which single (or lower
stage) operates on level rise.

“B” - operating differential single
(or lower stage) - drop in level to
restore switch to original position.

“C” - level at which upper stage
operates on level rise.

“D” - operating differential of upper
stage - drop in level to restore
switch to original position.

“E” - increase in level above “A” to
operate upper stage.

“A”

6-3/4˝

8˝

“B”

3/4˝

1-1/4˝

“C”
8-1/2˝
9-1/2˝

“D”
1-1/4˝
1-3/4˝

Single Stage with Wide

Differential “A” Not Adjustable

Sp. Gr.

1.0
.6

"C"

“A”
7-1/2˝
8-3/4˝

"E"

"B"

"A"

“E”
2-1/4˝
2-1/2˝

"D"

Code

C1-75

Code

C1-75

“B”

1-3/4˝

2˝

Two Stage Operation

“A”- Not Adjustable

Sp. Gr.

1.0

“A”

5-3/4˝

.6

7˝

LIQUID LEVEL CHANGES IN INCHES OF WATER FOR ­Series 1271,1273, 1274 - Minimum Specific Gravity 0.58

“B”

3/4˝

1-1/4˝

“C”

8˝

9-1/2˝

“D”

1-1/4˝

2˝

“E”
2-1/2˝
2-1/4˝

Single Stage Only

“A” Not Adjustable

Sp. Gr.

1.0
.58

FOR SERVICE OTHER THAN SATURATED STEAM

CONSULT FACTORY

PRESSURE RATINGS

One horizontal and one vertical 1˝ NPT pipe connection.

Minimum

Specific

Type

201
251

Gravity

0.6

0.75

0.75

“A”

6-11/16˝

8-1/4˝

Series 201, 251

Pressure Rating At

100°F

600 psi
1000 psi
1250 psi

750°F Max.

500 psi
750 psi
750 psi

“B”

1˝
2˝

Code

C1-60
C1-75
C1-75

and 650°F

Series 203, 253: (1) one vertical and (1) horizontal flanged connec-

Series 204, 254: Two vertical flanged connection (1˝ RF forged

Type

203

204

253
254

ypes 211, (1) vertical and (1) horizontal 1˝ NPT pipe connection

T
Type 213, (1) flange vertical and (1) flange horizontal 1˝ RF forged
steel.
Type 214, Both flanges vertical 1˝ RF forged steel.

Type

211
213

214

FLANGE AND FLOAT SPECIFICATIONS

tion (1˝ FR forged steel - ANSI specifications.)

steel - ANSI specifications).

Minimum

Specific

Gravity

0.6

0.75

0.75

Pressure Rating At

100°F

275 psi
600 psi
600 psi
275 psi

720 psi
1000 psi
1250 psi

750°F Max.

100 psi
425 psi
500 psi
100 psi
425 psi
750 psi
750 psi

Flange

Class PSI

150
300
600
150
300
600
600

and 650°F

Minimum

Specific

Gravity

0.6

0.6

Pressure Rating At

100°F

450 psi

275 psi

450 psi

450 psi

500°F Max.

300 psi
150 psi
300 psi
300 psi

Flange

Class PSI

--­150
300
600

Code

C1-160
C1-360
C1-660
C1-175
C1-375
C1-675
C1-675

Code

C1-60
C1-160
C1-360
C1-660